Whereas the Pass Labs preamplifiers are designed by Wayne Colburn, the power amplifiers are the work of company founder and high-end audio veteran Nelson Pass, who even lays out his own circuit boards. The X-model amplifiers, beginning with the X1000 in 1998, were the first implementation of Nelson Pass's patented Supersymmetry topology (see "Nelson Pass on the Patents of Pass"). The XA series, which debuted in 2002, combined Supersymmetry with the single-ended class-A operation of the Aleph series. The XA.5 models offer detail improvements over the XAs.

In more than 37 years of working at audio magazines, I have never reviewed an Electrocompaniet product. With this review of the company's ECD 2 digital/analog processor, which costs a dollar short of $3100, that streak of inattention has come to an end.

With the help of 20:20 hindsight, it looks as if I made a decision when I joined Stereophile: to review a loudspeaker from Wilson Audio Specialties every 11 years. In June 1991, I reported on Wilson's WATT 3/Puppy 2 combination, which cost $12,740/pair in an automotive gloss-paint finish. This was followed in July 2002 by my review of the Wilson Sophia ($11,700/pair). And now, in December 2013, I am writing about the Wilson Alexia, which costs a not-inconsiderable $48,500/pair.

When I became Stereophile's editor in 1986, the median age of the magazine's readership was the same age as I was then, 38; ie, half the readers were younger than 38, half older. According to our most recent reader survey, the median reader age is now 48, meaning that in the intervening 19 years, that median reader has aged at half the rate of the rest of us. A nice trick. But older that reader certainly has become, which has led to cries of doom from some quarters of the audio industry.

Wired with Transparent cables, the extreme audio system in the large room at the Denver Tech Center HyattdCS Vivaldi digital source, VTL TL7.5 III preamp, VTL Siegfried power amps, Wilson Alexandria XLF speakers driven full-range and twin Thor's Hammer subwoofers driven by 250Wpc Parasound Halo A 21 amplifiers below 38Hzworked its magic both on the disco-meets-EDM of Daft Punk's "Lose Yourself to Dance" and the delicate harmonic traceries of Dave Wilson's Debussy violin sonata recording transferred to DSD by Puget Sound's Bruce Brown. In both cases, there was a sense of loss when the music stopped. It is difficult to imagine how music reproduction could get any better than what I heard in this room the Saturday afternoon of the show!

Ray Kimber always gets great sound at shows, but this year, although he was still using four Sony SS-AR1 loudspeakers hooked up with Kimber Select cables and an EMM DAC to play his four-channel IsoMike DSD master files, there was something extra-magical happening in the room. Both pianist Fan-Ya Lin's album Emerging and the Romantic Album from violin and piano ensemble the Formosan Duo, sounded tangibly real. The key, it turned out were the gigantic, 300lb MTRX class-A/B monoblocks from EMM Labs, can be seen in my photo. This brute will output 1500W into 4 ohms and, in Ray Kimber's words, extracts "cheerful obedience" from the speakers it is tasked to drive.

John Siau of Benchmark (right) and Laurie Fincham of THX (left) gave a provocative presentation on the final morning of the show, entitled "Why Most 24-bit Audio Systems Still Deliver 16-bit Performance." The thesis was that even with D/A processors capable of operating with a dynamic range >20 bits, there is still the resolution bottleneck imposed by the amplifier. As I have pointed out in Stereophile's reviews, amplifiers with a sufficiently low noisefloor and a sufficiently large maximum voltage swing to equal hirez audio's dynamic range are a) rare and b) necessarily expensive. Benchmark, using the unique, high-efficiency amplifier modules designed by Laurie Fincham, Owen Jones (the twin brother of TAD's Andrew Jones), and Andrew Mason, that I wrote about in my 2012 CES report, aims to address both those issues.

Bel Canto's John Stronczer was excited. "The Powerstream amplifier's S/N ratio is 120dB measured at the speaker terminals!" I was impressed. This is equivalent to 20-bit digital audio, which means this digital-input monoblock, which costs $15,000 each, is one of the quietest amplifiers I have encountered. It offers 300W into 8 ohms, 1200W into 2 ohms. Audio data presented to the ST-optical inputs are reclocked and then converted to analog with a BurrBrown PCM1792. The analog signal is then fed to an output stage based on the well-regarded Hypex class-D modules, used in a proprietary low-gain configuration to maximize dynamic range.

Listening to Scaena's Silver Ghost speakers ($153,000/system) had been a highlight of last March's AXPONA in Chicago. At the Denver Tech Center Hyatt, the speakers had been set-up by Sunny Umrao (in photo) firing diagonally across a much larger room than in Chicago. With a system comprising a dCS Vivaldi digital source driving an Audio Research Reference 75 stereo amplifier for the towers and six inexpensive Crown class-D amplifiers for the six woofer modules operating below 120Hz, the sound of a live recording of Dave Brubeck's "Rondo a la Turk" did indeed sound live.

I always enjoy visiting the MBL room at a show. Not only I am addicted to the quality of the German company's "Radialstrahler" omnidirectional tweeter, which has a delicacy to its presentation that escapes conventional dome units, but MBL North America's Jeremy Bryan is obsessive about set-up. His RMAF system comprised the MBL 116f speakers ($29,000/pair) driven by a pair of MBL C15 amplifiers ($12,500/pair), a C11 preamplifier ($8800), and a C31 CD player/D/A processor ($9200), all hooked up with WireWorld Eclipse cables. (The electronics are all from MBL's Corona line.)